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#ifndef UTIL_FLOAT_H_2020227_
#define UTIL_FLOAT_H_2020227_
#include "FloatX.h"
#include <boost/optional.hpp>
#include <cerrno>
#include <string>
#include <type_traits>
namespace util {
template <typename Float>
boost::optional<Float> full_string_to_float(const std::string &s) {
static_assert(
std::is_same<Float, float>::value ||
std::is_same<Float, double>::value ||
std::is_same<Float, long double>::value,
"Floating-point type not supported by this function");
// NOTE: Don't use std::istringstream: it doesn't support hexfloat.
// Don't use std::sto{f,d,ld} either: they throw std::out_of_range on denormals.
// Only std::strto{f,d,ld} are sane, for some definitions of sane...
const char *const str = s.c_str();
char *end;
Float value;
errno = 0;
if (std::is_same<Float, float>::value) {
value = std::strtof(str, &end);
} else if (std::is_same<Float, double>::value) {
value = std::strtod(str, &end);
} else {
value = std::strtold(str, &end);
}
if (errno) {
if ((errno == ERANGE && (value == 0 || std::isinf(value))) || errno != ERANGE) {
return boost::none;
}
}
if (end == str + s.size()) {
return value;
}
return boost::none;
}
}
#endif
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